The invention relates to a medical radio high frequency coagulation instrument. More specifically, the invention relates to a medical radio frequency coagulation instrument with a preferably circular cylindrical instrument shaft which has, at the proximal end, two electrically conductive coagulation ring electrodes which are arranged inside one another and preferably concentric to one another and to the shaft axis. Electrically conductive mutually insulated tubular feedlines extend rearwardly from the electrically conductive coagulation ring electrodes, are preferably formed in one piece therewith, and also, are preferably arranged concentric to one another and to the shaft axis, with the distal end of the tubular feedlines being connected to a connection piece for the supply of the required radio frequency current.
In a known electro-surgical treatment instrument of this kind (DE-OS 41 22 219) the two coagulation electrodes cooperate with a cutting electrode arranged concentrically to them. The coagulation electrodes are placed in use onto the tissue or vessel to be coagulated, whereupon the radio frequency coagulation current is switched on by means of a control device for a period until the desired coagulation has been carried out through the current flow between the two coagulation electrodes.